Russian Talmudist; died at Wilna in 1671 or 1672. He was a member of a Prague family, but settled early in life at Wilna. In 1655, in consequence of the war between Poland and Russia, he was compelled to flee from the city, leaving all his property behind. He then settled at Amsterdam, and owing to his great Talmudical knowledge was befriended by Saul Morteira and Isaac Aboab. On the reestablishment of peace between Poland and Russia, Ribkas returned to Wilna, where his affairs seem to have prospered. At his death he bequeathed a great part of his fortune to charitable institutions which are still administered by his descendants.

While at Amsterdam Ribkas was charged with the revision of the proofs of a new edition of the Shulḥan 'Aruk, which was being prepared in the printing-office of Proops. This new edition (Amsterdam, 1661-67) was provided by Ribkas with marginal notes of his own, entitled "Be'er ha-Golah," in which he gives the sources of the halakot, besides short comments. In addition to this work, which has always been reprinted in the margins of the Shulḥan'Aruk, Ribkas left in manuscript "Kelale ha-Hora'ah," giving the final decisions in regard to halakot, and "Keli ha-Golah," a commentary on the Mishnah.